Machine for applying a locking patch to a threaded element



United States Patent Inventor George F. C. Burke,

Beverly, Massachusetts Appl. No. 810,913

Filed Mar. 20, 1969 l Continuation of Ser. No. 672,347, Oct. 2, 1967Patented Sept. 29, 1970 Assignee USM Corporation Boston, Massachusetts acorporation of New Jersey MACHINE FOR APPLYING A LOCKING PATCH TO ATHREADED ELEMENT 14 Claims, 5 Drawing Figs.

US. Cl 118/620, 118/62, 118/308, 118/319 Int. Cl 1305c 5/00 Field 01'Search 1 18/620,

[56] References Cited UNITED STATES PATENTS 309,243 12/1884 Patch1l8/502X 1,153,679 9/1915 Elliot 118/230 1,334,017 3/1920 Cooley 118/622,198,999 4/1940 Jeffery ll8/319X 2,422,417 6/1947 Hutchinson l 18/620UX3,291,631 12/1966 Smith 1 18/308 3,306,309 2/1967 Pahl et a1. 3,323,4926/1967 Mellar et al. 3,416,492 12/1968 Greenleaf 1 18/620 PrimaryE.raminer lohn P. McIntosh At!orneysW. Bigelow Hall and Richard A. WiseABSTRACT: A machine for applying a locking patch to elements, themachine having a rotatable wheel with a plurality of removable holdersto carry the elements sequentially and individually through a heatingstation, a patch applying station and a removal station.

MACHINE FOR APPLYING A LOCKING PATCH TO A THREADED ELEMENT BACKGROUND OFTHE INVENTION This application is a continuation of application Ser. No.672,347, filed Oct. 2, I967.

This invention relates to improvements in a machine for applying aretarder patch" to a threaded element. The patch is designed to increasethe frictional engagement between the threaded element and its matingthreaded surface and is applied by the method disclosed in U. S. Pat.application Ser. No. 628,683 filed Apr. 5, 1967 in the name of R. J.Duffy.

It has been proposed heretofore to apply a retarder patch" to a threadedelement by depositing a plastic material in the desired location on thefastener by positioning, contiguous with the fastener, an apparatus suchas a die, filling the cavity with the plastic and thereafter heating thedie, fastener and plastic to fuse the plastic material to the threadsurface of the fastener.

It has further been proposed to utilize an open cavity in a suitablenon-conductive material with the electrically charged fastener restingtherein. The exposed surface of the fastener is appropriately shieldedto define the shape of the desired patch and a particulate plasticmaterial is electrostatically disposed thereon. The entire assembly isthen heated to cause a fusing between the fastener and the plasticmaterial.

Although a plastic patch applied by either of these methods provides alocking action between mating threaded elements, the steps of bringingeach fastener element into register with the receptacle, supplying theplastic and then heating the entire combination, has proven to be bothtime consuming and expensive.

A through feed apparatus for applying locking patches to headed,threaded fasteners is the subject matter of U. S. Pat. application Ser.No. 640,639 filed May 23, I967 in the name of George F. C. Burke et al.This machine carries the fasteners through a series of work stations bysuspending the fasteners by their heads between a pair ofbelts.

The prior Burke apparatus, while eliminating to a large extent theshortcomings of the other methods is limited in the fact that onlyheaded fasteners may beprocessed.

SUMMARY OF THE INVENTION It is an object of this invention to provide amechanism by which a locking patch may be applied to a threaded fastenerwhether or not they are headed and in an inexpensive and rapid fashion.

In accordance with this object and as a feature of this invention, thereis provided a manually fed machine which will carry a threaded fastenerthrough a plurality of stations which prepare the fastener to receivethe patch and apply the patch.

It is another object ofthis invention to provide a machine to handlefasteners of the socket type and to apply a locking patch thereto.

in accordance with this object as another feature of this inventionthere is provided a rotating wheel having a plurality of radiallyextending pins which are ofa size suitable to securely hold a sockettype fastener with the socket placed over the pin. These pins are easilyremovable and they can be replaced witha pin of a different size when adifferent size fastener is being used.

Other and further objects are to provide a machine which will provide asocket type threaded fastener, of either the headed or headless type,with a plastic coating sufficient in size and form to provide thenecessary self-locking torque with a complementary threaded matingelement. The processed fasteners need have no more than standarddimensional limits and the plastic coating will form without theapplication of shaping or molding pressures, a patch of plastic materialsecurely bonded to the root flank and crest surfaces throughout alimited angular extent and for a predetermined number ofthreadedconvolutions.

Yet, another object of this invention is to provide a machine which willrapidly and easily apply a patch to any socket headed element.

A further object of this invention is a machine to provide a lockingpatch to a socket type threaded element without resort to auxiliaryapparatus such as heaters or the like.

The above and other features of the invention including various noveldetails of construction and combinations of parts will now be moreparticularly described with reference to the accompanying drawings andpointed out in the claims.

It will be understood that the particular machine embodying theinvention is shown by way of illustration only and not as a limitationof the invention. The principles and features of this invention may beemployed in varied and numerous embodiments without departing from thescope of the invention.

DESCRIPTION OF THE DRAWINGS FIG. 1 is an elevational view of anillustrative patch applying machine embodying the present invention;

FIG. 2 is a view partly in section on an enlarged scale of an elementholding pin and its fastening means;

FIG. 3 is a sectional view of the pin with an element mounted thereonshowing the relationship of the element with the heater taken alonglines III-Ill of FIG. 1;

FIG. 4 is a sectional view of the pin mounted thereon showing arelationship of the element of the patch applying means taken alonglines IVIV of FIG. I; and

FIG. 5 is a sectional view of the pin with an element mounted thereonshowing the relationship with the discharge means along lines V-V ofFIG. 1.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The illustrative machine asseen in FIG. 1 comprises a frame 2 upon which is mounted for rotation ashaft 4 supported by journals 6. Frictionally mounted upon the shaft 4is a circular frame disc 8 having a plurality of clamps 10 mounted nearits periphery. Suspended beneath the frame two and connected to the disc8 by means of pulleys 12, I4 and belt 16 is a motor 18. Mounted abovethe frame 2 is a vertically adjustable induction heater coil 20 to bedescribed in greater detail later. Adjacent the heater along thedirection of feed is the patch applying station which is mounted upon avertically rigid shaft 32 but is adjustable along said shaft by means ofa bracket and bolt assembly 34. Briefly, the patch aapplying stationcomprises a motor 36 which drives a belt 38 which turns a screw feed(not shown) within a hopper 40 to meter the plastic material held withinthe hopper to the fasteners 22 as they pass by thenozzle 42 of theapplying station.

The fasteners 22 which are treated by the patch applying apparatus arecarried through the various work stations mounted upon the outer end ofpins removably mounted in the clamps 10. An operator places a fastenerwhich has' a socket head upon the outer end of the pin 50 as the wheel 8rotates at a suitable pace under operator control. The fastener whichhas been properly prepared is then carried through the field of theinduction heater coil 20 whereat it is heated to the appropriatetemperature. The fastener then passes by the nozzle 32 of the patchstation 30 whereat the plastic material is disposed upon the heated,threaded surface. The pins 50 continue to carry the threaded fasteners22 in a circular path until the removal station 52 is reached whereat asteady stream of air is fed through tube 54 a pair of nozzles and thendirected in a generally radial direction outwardly blowing the fastener22 off the pin 50 into receptacles or perhaps upon a moving belt forfurther coiling.

Since the apparatus is manually fed, the disc 8 rotates at a relativelyslow rate and further included for safety is a friction drive betweenthe pulley I2 and the shaft 14 allowing the operator, if necessary, tostop rotation of the disc without endangering his person or damaging themachine.

As can thus be seen in FIGS. 2 and 3, the clamps 10 which are mountedupon the disc 8 comprise a pair of U-shaped inwardly sprung membersmounted in parallel relation along a radius of the disc 8 and whichreceive one pin 50. The pin in turn, comprises a main body portion of asuitable heat resistant material such as treated asbestos which tapersto a hollow truncated point into which is placed an insert 60 of anysuitable material such as a ceramic or an appropriate metal. It shouldagain be emphasized that the pins 50 are readily replaceable so that ifit is desired to place the patch upon screws having a different sizedsocket, all that the-operator need do is remove the pins 50 and replacethem with ones of an appropriate size.

FIG. 3 illustrates the relationship between the disc 8, a pin 50, afastener 22, and the heater coil while the pin is passing through theheating station. The heater coil 20 is found in a loop having segments20a and 20b The fasteners 22 pass between the segments which are curved(see FIG. 1) to conform to a mean circular path of fasteners ofdifferent lengths. The loop is vertically adjustable through a selectedrange to accommodate the different length fasteners withoutinterference. It is to be noted that the fastener 22 is removably seatedupon the pin 60 and extends upwardly to a position directly between thetwo arms of the heater coil 20. In the event that the fastener was oneof the greater length, the heater assembly need only be adjusted alongits vertical shaft to apply heat to the fastener at the appropriatelengthwise position.

FIG. 4 illustrates the relationship of the fastener 22 as it passes thenozzle 42 of the patch applying station. The particulate plasticmaterial is forced through nozzle 42 and impinges the heated portion ofthe fastener 22 whereat it becomes viscous and adheres tothe threadedsurface. A vacuum mouth 66 is placed directly opposite the nozzle 42 torecover any of the particulate plastic which does not adhere to theplastic.

FIG. 5 illustrates relationship of the fastener 22 at the removalstation whereat a pair of nozzles 70 connected by tube 54 to a standardair supply presents sufficient outwardly directed force to the fastener22 to remove it from the end of the pin 50. V

Having thus described my invention, what I claim as new and desire tosecure by Letters Patent of the United States isz l. A machine forapplying locking patches to threadedelements comprising a rotatablewheel, means for holding a plurality of threaded elements on said wheeland adjacent the periphery thereof with a threaded portion of eachelement extending outwardly from the wheel, a plurality of work stationsdisposed adjacent the periphery of said wheel including a station havingan arcuate heater located for heating the threaded portion of an elementon said wheel, a station having means for applying a locking patch to athreaded portion of an element held on said wheel, a station havingmeans for automatically ejecting an element located thereat from saidwheel, and

means for rotating said wheel such that an element so retained by saidholding means is passed seriatim through said heating station, saidpatch applying station and said ejecting station.

2. The machine set forth in claim 1 wherein said holding means comprisesa mounting piece which is readily removable from said wheel forreceiving a threaded element to be provided with a locking patch.

3. The machine set forth in claim 2 wherein said threaded elements arefasteners having socket-type heads and said mounting piece comprises apin having an end portion adapted for insertion into the socket of athreaded element to be provided with a locking patch.

4. The machine set forth in claim 3 wherein said mounting pin isdisposed on said wheel with said end portion extending radiallyoutwardly from said wheel.

5. The machine set forth in claim 4 wherein said mounting means furtherincludes a clip having an opening provided for receiving said mountingpin in readily removable engagement.

6. A machine for applying locking patches to threaded elementscomprising a rotatable wheel, a plurality of radially extending pinsmounted adjacent the periphery of said wheel for receiving the threadedelements thereon, an arcuate heater mounted adjacent said wheel, meansmounted adjacent said wheel for applying a locking patch to a threadedportion of an element received on said wheel, and an ejector meansdisposed adjacent said wheel, rotation of said wheel being effective tocarry threaded elements placed on said pins in a predetermined pathwherein an element is subjected to said heater, said patch applyingmeans, and then automatically ejected from the pins, readying each pinto receive another element for processing.

7. A machine as in claim six and further including means for detachablyretaining said pins on said wheel.

8. A machine as in claim 7 wherein said retaining means comprises aplurality of clips.

9. A machine as in claim 6 wherein the heater is of the induction type.

10. A machine as in claim 9 wherein the heating station comprises a coilwhich is curved to conform to the mean circular path of different lengthfasteners.

11. A machine as in claim 6 wherein the heating station comprises a coilhaving two arcuate segments spaced on either side of the path of thefastener.

12. A machine as in claim 6 wherein the pins are of a heat resistantmaterial.

13. A machine as in claim 6 wherein each pin has a truncated conical endportion having an insert which extends beyond the truncated surface.

14. A machine as in claim 6 wherein the ejector means comprises an airnozzle directed in a radial direction with respect to the wheel andwhich directs a stream of air approximately parallel to the pins.

